package thread;
import java.util.*;
/**
 * 并发安全的集合API:
 * ArrayList、LinkedList、HashSet都不是并发安全的(异步)
 */
public class SyncDemo4 {
    public static void main(String[] args) {
        //List<Integer> c = new ArrayList<>();
        //List<Integer> c = new LinkedList<>();
        //Set<Integer> c = new HashSet<>();

        //List<Integer> c = Collections.synchronizedList(new ArrayList<>());
        //List<Integer> c = Collections.synchronizedList(new LinkedList<>());
        Set<Integer> c = Collections.synchronizedSet(new HashSet<>());
        Thread t1 = new Thread(){
            public void run(){
                for(int i=0;i<1000;i++){
                    c.add(i);
                }
            }
        };
        Thread t2 = new Thread(){
            public void run(){
                for(int i=1000;i<2000;i++){
                    c.add(i);
                }
            }
        };
        t1.start();
        t2.start();

        try {
            Thread.sleep(50);
        } catch (InterruptedException e) {
        }
        System.out.println(c.size()); //2000?
    }
}













